Hydrogenated nitrile rubber and preparation method thereof

Abstract

The invention discloses hydrogenated butadiene-acrylonitrile rubber and a preparation method thereof.The method comprises the steps that butadiene-acrylonitrile rubber liquid is subjected to a double-decomposition reaction to obtain a double-decomposition reaction mixture, in the presence of a hydrogenation catalyst system, the double-decomposition reaction mixture makes contact with hydrogen under the hydrogenation reaction condition to obtain a hydrogenation reaction mixture, and the hydrogenation reaction mixture is subjected to a hydrogenation reaction to obtain hydrogenated butadiene-acrylonitrile rubber. The hydrogenation catalyst system contains a hydrogenation catalyst, a ligand and an auxiliary agent, and the auxiliary agent is selected from one or more than two of compounds shown as a formula II. According to the preparation method of the hydrogenated butadiene-acrylonitrile rubber, the hydrogenation reaction activity can be obviously improved, the reaction speed can be increased, the reaction time can be shortened, and the Mooney viscosity of the product can be effectively reduced. (AoM) pYq (Formula II).

Description

Technical Field

[0001] The invention relates to hydrogenated nitrile rubber and a preparation method thereof. Background Art

[0002] Hydrogenated nitrile rubber is generally prepared by selective hydrogenation of nitrile rubber. Due to the special structure, it has excellent oil resistance, high temperature resistance, high pressure resistance, oxidation resistance and mechanical properties. It is a special rubber with excellent comprehensive performance and has been widely used in aerospace, oil exploration, automobile manufacturing and other fields.

[0003] Due to the high cost of nitrile rubber hydrogenation catalysts, complex hydrogenation processes, and harsh hydrogenation reaction conditions, the price of its products has remained high, which has seriously hindered the further expansion of its application areas and scope of use. In recent years, the focus of research on hydrogenated nitrile rubber has been concentrated on the following aspects: first, to find cheap metal catalysts to complete selective hydrogenation reactions to reduce catalyst costs; second, to improve the hydrogenation efficiency of existing catalytic systems through various means to achieve the purpose of reducing catalyst usage and improving production efficiency; third, to continuously improve catalyst recovery efficiency and reduce catalyst residues in products; fourth, to improve the comprehensive performance of products (including product processing performance, mechanical properties, etc.), and continuously expand the application field and use effect of hydrogenated nitrile rubber.

[0004] However, the Mooney viscosity of nitrile rubber increases significantly during the hydrogenation process, and the hydrogenation efficiency of the hydrogenation catalyst is low, which has not been well solved.

[0005] Therefore, there is an urgent need to solve the problem that the Mooney viscosity of nitrile rubber increases significantly during the hydrogenation process and the hydrogenation efficiency of the hydrogenation catalyst is low. Summary of the invention

[0006] The purpose of the present invention is to overcome the defects of the prior art method that the Mooney viscosity of hydrogenated nitrile rubber increases significantly after hydrogenation and the hydrogenation reaction efficiency of the hydrogenation catalyst is low, and to provide a method for preparing hydrogenated nitrile rubber with high hydrogenation reaction activity and significantly improved product Mooney viscosity.

[0007] According to a first aspect of the present invention, the present invention provides a method for preparing a hydrogenated nitrile rubber, wherein the method comprises the following steps:

[0008] (1) dissolving the nitrile rubber in an organic solvent to obtain a nitrile rubber solution;

[0009] (2) subjecting the nitrile rubber solution to a metathesis reaction under olefin metathesis reaction conditions to obtain a metathesis reaction mixture;

[0010] (3) contacting the metathesis reaction mixture with hydrogen under hydrogenation reaction conditions in the presence of a hydrogenation catalyst system to obtain a hydrogenation reaction mixture, wherein the hydrogenation catalyst system comprises a hydrogenation catalyst, a ligand and an auxiliary agent;

[0011] The hydrogenation catalyst is one or more selected from the compounds represented by formula I-1 and the compounds represented by formula I-2.

[0012] M 1 a M 2 b X m L n (Formula I-1)

[0013] In Formula I-1, M 1 Rhodium, M 2 For ruthenium,

[0014] m X are the same or different and are each independently chlorine, bromine or hydrogen,

[0015] n L's are the same or different, and are each independently an organic phosphine, an organic cerium, a nitrogen-containing organic compound, a sulfur-containing organic compound, or an oxygen-containing organic compound,

[0016] 1≤a≤6, 1≤b≤3, 3≤m≤7, 6≤n≤21;

[0017] (R x B) z R y (Formula I-2)

[0018] In formula I-2, x R are the same or different and are independently selected from C1-C8 alkyl, C4-C8 cycloalkyl, C6-C 15 Aryl or C7-C 15 The aralkyl group,

[0019] B is phosphorus, arsenic, sulfur or sulfoxide,

[0020] y T are the same or different, and each independently represents hydrogen or an anion,

[0021] z is 2, 3 or 4, x is 2 or 3, y is 1, 2 or 3;

[0022] The auxiliary agent is one or more compounds selected from the group consisting of:

[0023] (A o M) p Y q (Formula II)

[0024] In formula II, o A's are the same or different and are independently C1-C8 alkyl, C4-C8 cycloalkyl, C6-C 15 Aryl or C7-C 15 The aralkyl group,

[0025] M is phosphorus or arsenic,

[0026] q Y are the same or different and are each independently an anion,

[0027] o is 3, 4, 5 or 6, p is 1, 2 or 3, and q is 1, 2 or 3.

[0028] According to a second aspect of the present invention, the present invention provides a hydrogenated nitrile rubber prepared by the method of the present invention.

[0029] The preparation method of hydrogenated nitrile rubber according to the present invention can not only significantly improve the hydrogenation reaction activity, increase the reaction speed, shorten the reaction time, and increase the hydrogenation degree of the product, but also effectively reduce the Mooney viscosity of the product.

[0030] Other features and advantages of the present invention will be described in detail in the following detailed description. DETAILED DESCRIPTION

[0032] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0033] According to a first aspect of the present invention, the present invention provides a method for preparing a hydrogenated nitrile rubber, the method comprising the following steps:

[0034] (1) dissolving the nitrile rubber in an organic solvent to obtain a nitrile rubber solution;

[0035] (2) subjecting the nitrile rubber solution to a metathesis reaction under olefin metathesis reaction conditions to obtain a metathesis reaction mixture;

[0036] (3) contacting the metathesis reaction mixture with hydrogen under hydrogenation reaction conditions in the presence of a hydrogenation catalyst system to obtain a hydrogenation reaction mixture, wherein the hydrogenation catalyst system comprises a hydrogenation catalyst, a ligand and an auxiliary agent.

[0037] According to the method of the present invention, in step (1), the mass percentage concentration of acrylonitrile-butadiene rubber in the acrylonitrile-butadiene rubber glue (that is, the percentage value of the mass of acrylonitrile-butadiene rubber and the mass sum of acrylonitrile-butadiene rubber and organic solvent) is not particularly limited and can be a concentration commonly used in the art. Preferably, in the acrylonitrile-butadiene rubber glue, the mass percentage concentration of acrylonitrile-butadiene rubber is 2-15%. More preferably, in the acrylonitrile-butadiene rubber glue, the mass percentage concentration of acrylonitrile-butadiene rubber is 4-12%. Further preferably, in the acrylonitrile-butadiene rubber glue, the mass percentage concentration of acrylonitrile-butadiene rubber is 6-10%.

[0038] According to the method of the present invention, in step (1), the nitrile rubber may be various nitrile rubbers containing carbon-carbon double bonds (C=C) and cyano groups (-CN), and may be binary nitrile rubber and / or ternary nitrile rubber. Specific examples of the nitrile rubber may include, but are not limited to, butadiene-acrylonitrile rubber, butadiene-(methyl)acrylonitrile rubber, 2-methyl-1,3-butadiene-acrylonitrile rubber, 2-methyl-1,3-butadiene-(methyl)acrylonitrile rubber, butadiene-acrylonitrile-acrylic rubber, butadiene-acrylonitrile-methyl acrylate rubber, butadiene-acrylonitrile-ethyl acrylate rubber, butadiene-acrylonitrile-tert-butyl acrylate rubber, butadiene-acrylonitrile-butyl acrylate rubber, butadiene-acrylonitrile-(meth)acrylic rubber, butadiene-acrylonitrile-methyl (meth)acrylate rubber, butadiene-acrylonitrile-ethyl (meth)acrylate rubber, butadiene-acrylonitrile-tert-butyl ... One or more of butadiene-acrylonitrile-(meth)acrylate butyl rubber, butadiene-(meth)acrylonitrile-acrylic rubber, butadiene-(meth)acrylonitrile-methyl acrylate rubber, butadiene-(meth)acrylonitrile-ethyl acrylate rubber, butadiene-(meth)acrylonitrile-tert-butyl acrylate rubber, butadiene-(meth)acrylonitrile-butyl acrylate rubber, butadiene-(meth)acrylonitrile-(meth)acrylic rubber, butadiene-(meth)acrylonitrile-methyl (meth)acrylate rubber, butadiene-(meth)acrylonitrile-ethyl (meth)acrylate rubber, butadiene-(meth)acrylonitrile-tert-butyl (meth)acrylate rubber and butadiene-(meth)acrylonitrile-butyl (meth)acrylate rubber.

[0039] Preferably, the acrylonitrile rubber is butadiene-acrylonitrile rubber and / or butadiene-(methyl)acrylonitrile rubber.When the acrylonitrile rubber is a mixture of butadiene-acrylonitrile rubber and butadiene-(methyl)acrylonitrile rubber, the present invention has no requirements for the ratio of butadiene-acrylonitrile rubber and butadiene-(methyl)acrylonitrile rubber adding, and can be any ratio.According to the method of the present invention, the cyano content in the acrylonitrile rubber can be conventionally selected.Preferably, the cyano content in the acrylonitrile rubber is 20-50% by weight.The cyano content adopts nuclear magnetic resonance spectroscopy to measure.

[0040] According to the method of the present invention, in step (1), the organic solvent can be various organic solvents that can dissolve nitrile rubber. Specifically, the organic solvent can be one or more of aromatic hydrocarbons, halogen-substituted aromatic hydrocarbons, halogenated alkanes, ketones, oxacycloalkanes and amides. Preferably, the organic solvent is one or more of benzene, toluene, xylene, chlorobenzene, dichlorobenzene, trichlorobenzene, acetone, butanone, tetrahydrofuran, dioxane and N,N-dimethylformamide.

[0041] According to the method of the present invention, step (1) preferably includes degassing the nitrile rubber glue. The nitrile rubber glue can be degassed by filling an inert gas into a container containing the nitrile rubber glue, then degassing, and repeating the filling and degassing at least three times, thereby degassing the nitrile rubber glue.

[0042] According to the method of the present invention, in step (2), the metathesis reaction is preferably carried out in the presence of a molecular weight regulator. The molecular weight regulating catalyst may be one or more selected from the group consisting of the compound represented by formula III and the compound represented by formula IV.

[0043]

[0044] In formula III and formula IV, G1 and G2 are each hydrogen, C2-C 20 Substituted or unsubstituted alkenyl, C2-C 20 Substituted or unsubstituted alkynyl, C1-C 20 Substituted or unsubstituted alkyl, C6-C 20 Substituted or unsubstituted aryl, C1-C 20 Carboxylate group, C1-C 20 Substituted or unsubstituted alkoxy, C2-C 20 Substituted or unsubstituted alkenyloxy, C2-C 20 Substituted or unsubstituted alkynyloxy, C6-C 20 Substituted or unsubstituted aryloxy, C1-C 20 Substituted or unsubstituted alkylthio, C1-C 20 substituted or unsubstituted alkylsulfonyl, or C1-C 20 A substituted or unsubstituted alkylsulfinyl group.

[0045] In formula III and formula IV, G1 and G2 are each preferably C6-C 20 The substituted or unsubstituted aryl group is more preferably a phenyl group.

[0046] In formula III and formula IV, E1, E2, E3 and E4 are each anionic ligands. In formula III and formula IV, E1, E2, E3 and E4 can be various common anionic ligands, for example, each can be a halogen ion, preferably a chloride ion.

[0047] In formula III, H is an anionic ligand.

[0048] In formula III, c is an integer of 1-6.

[0049] In Formula III and Formula IV, F1, F2, F3 and F4 are each a neutral ligand.

[0050] In formula III and formula IV, F1, F2, F3 and F4 can each be a common neutral ligand, and specific examples thereof can include but are not limited to: phosphine, amine, thioether, carbene, or substituted or unsubstituted imidazolidine. Preferably, in formula III and formula IV, F1, F2, F3 and F4 are each phosphine, carbene, or substituted or unsubstituted imidazolidine. More preferably, in formula III, F1 is a phosphine. More preferably, in formula III, F2 is a substituted or unsubstituted imidazolidine. In a more preferred embodiment, in formula III, F1 is a phosphine and F2 is a substituted or unsubstituted imidazolidine. In another more preferred embodiment, in formula IV, F4 and F3 are each substituted or unsubstituted imidazolidine, or a phosphine, and the phosphine is preferably a trialkyl phosphine.

[0051] The phosphine may be a compound in which the hydrogen in various phosphine molecules is partially or completely replaced by an organic group, wherein the organic groups are the same or different and each may be selected from a chain alkyl group (such as C1-C 10 Alkyl) and substituted or unsubstituted cycloalkyl (such as C6-C 12 The phosphine is preferably a trialkylphosphine, more preferably a tricyclohexylphosphine.

[0052] The substituted or unsubstituted imidazolidine may be an imidazolidine represented by formula V,

[0053]

[0054] In Formula V, G3 and G4 are the same or different and are each independently C6-C 20 A substituted or unsubstituted aryl group.

[0055] In Formula V, G3 and G4 are the same or different and are each independently preferably G5, G6, G7, G8 and G9 are the same or different, and each can be hydrogen or a C1-C5 alkyl group. The C1-C5 alkyl group includes a C1-C5 straight-chain alkyl group and a C3-C5 branched-chain alkyl group, and specific examples thereof can include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl and n-pentyl.

[0056] In Formula V, G3 and G4 are more preferably

[0057] In Formula V, G3 and G4 are further preferably

[0058] In a preferred embodiment of the present invention, in formula III, G1 is phenyl, F1 is phosphine, F2 is substituted or unsubstituted imidazolidine, E1 and E2 are chloride ions, and H is iodide ion. In another preferred embodiment of the present invention, in formula IV, G2 is phenyl, F3 is phosphine, F4 is substituted or unsubstituted imidazolidine, and E3 and E4 are chloride ions.

[0059] In a more preferred embodiment of the present invention, in Formula III, G1 is phenyl, F1 is phosphine, and F2 is E1 and E2 are chloride ions, and H is an iodide ion. In another more preferred embodiment of the present invention, in formula IV, G2 is phenyl, F3 is phosphine, and F4 is E3 and E4 are chloride ions.

[0060] According to the method of the present invention, in step (2), the consumption of the molecular weight regulating catalyst can be appropriately selected according to the quality of the acrylonitrile-butadiene rubber, so as to achieve catalytic function. Generally, the consumption of the molecular weight regulating catalyst can be 0.002-5 weight % of the acrylonitrile-butadiene rubber total amount, preferably 0.005-1 weight % of the total amount of the acrylonitrile-butadiene rubber, more preferably 0.006-0.5 weight % of the total amount of the acrylonitrile-butadiene rubber, further preferably 0.02-0.1 weight % of the total amount of the acrylonitrile-butadiene rubber.

[0061] According to the method of the present invention, in step (2), from the perspective of further improving the regulating ability of the molecular weight regulating catalyst, the contact between the nitrile rubber solution and the molecular weight regulator catalyst is preferably carried out in the presence of at least one regulator, and the regulator can be an olefin.

[0062] The olefin used as the regulator can be one or more of a monoolefin, a diolefin and a polyolefin (i.e., an olefin molecule containing three or more carbon-carbon double bonds). The olefin used as the regulator is preferably a olefin of the general formula C k H 2k The hydrocarbon represented by , wherein k can be an integer greater than 2, preferably an integer from 2 to 20.

[0063] In a preferred embodiment of the present invention, the regulator is one or more selected from olefins, such as C2-C 20 Preferably, the regulator is one or more selected from α-olefins, so that the metathesis reaction can be carried out under milder conditions. Further preferably, the regulator is selected from C2-C 20 One or more of the α-olefins of the present invention, such as one or more of ethylene, 1-propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-dodecene, 1-hexadecene, 1-octadecene and 1-eicosene. More preferably, the regulator is C2-C 10 One or more of the α-olefins, for example, one or more of ethylene, 1-propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene and 1-decene.

[0064] The amount of the conditioning agent can be selected according to the expected molecular weight of the acrylonitrile-butadiene rubber. Preferably, the quality of the conditioning agent is 1-80% of the quality of the acrylonitrile-butadiene rubber. More preferably, the quality of the conditioning agent is 5-60% of the quality of the acrylonitrile-butadiene rubber. Further preferably, the quality of the conditioning agent is 10-50% of the quality of the acrylonitrile-butadiene rubber.

[0065] According to the method of the present invention, in step (2), the nitrile rubber glue is contacted with the molecular weight regulator and an optional regulator to reduce the molecular weight of the nitrile rubber. The reduction range of the molecular weight can be selected according to the intended use of the nitrile rubber.

[0066] According to the method of the present invention, in step (2), the olefin metathesis reaction conditions can be conventionally selected. Generally, the temperature of the metathesis reaction can be 30-150°C, preferably 40-120°C, more preferably 45-100°C, and further preferably 45-80°C. The time for contacting the nitrile rubber glue with the molecular weight regulating catalyst can be appropriately selected according to the temperature of contact, so as to obtain the expected molecular weight. Generally, the contact time of the nitrile rubber glue with the molecular weight regulating catalyst can be 0.01-4 hours, preferably 0.1-3 hours, more preferably 0.2-2 hours, and further preferably 0.5-1 hours.

[0067] According to the method of the present invention, in step (3), the hydrogenation catalyst is one or more selected from the compounds represented by formula I-1 and the compounds represented by formula I-2.

[0068] M 1a M 2 b X m L n (Formula I-1);

[0069] (R x B) z R y (Formula 1-2).

[0070] In Formula I-1, M 1 Rhodium, M 2 For ruthenium.

[0071] The m Xs are the same or different and are independently chlorine, bromine or hydrogen. Preferably, in formula I-1, X is chlorine.

[0072] n L are the same or different, and are each independently one or more of an organic phosphine, an organic bisphosphine, an organic cerium, a nitrogen-containing organic compound, a sulfur-containing organic compound or an oxygen-containing organic compound. The organic phosphine may be an organic monophosphine or an organic bisphosphine. Preferably, in formula I-1, L is an organic monophosphine. More preferably, in formula I-1, L is triphenylphosphine.

[0073] In formula I-1, a, b, m and n are each integers, wherein 1≤a≤6, 1≤b≤3, 3≤m≤7, and 6≤n≤21.

[0074] In a preferred embodiment, in Formula I-1, M 1 Rhodium, M 2 is ruthenium, X is chlorine, and L is an organic monophosphine, preferably triphenylphosphine. In this preferred embodiment, in formula I-1, a:b is 1-3:1, preferably, a:b is 2:1.

[0075] In a preferred embodiment, in Formula I-1, M 1 Rhodium, M 2 is ruthenium, X is chlorine, L is triphenylphosphine, a is 2, b is 1, m is 4, and n is 9. In another preferred embodiment, in formula I-1, M 1 Rhodium, M 2 is ruthenium, X is chlorine, L is triphenylphosphine, a is 3, b is 1, m is 5, and n is 12. In another preferred embodiment, in formula I-1, M 1 Rhodium, M 2 is ruthenium, X is chlorine, L is triphenylphosphine, a is 1, b is 1, m is 3, and n is 6.

[0076] Compound M represented by formula I-1 1 a M 2 b Xm L n It can be prepared by a method comprising the following steps:

[0077] (1) Add L and solvent into a reaction flask and reflux to dissolve under stirring;

[0078] (2) The M 1 Metal halides and M 2 The metal halides are mixed and dissolved in a hot solvent, and added into a reaction bottle at reflux temperature to react;

[0079] (3) Removing the solvent to obtain a crystalline or powdery hydrogenation catalyst.

[0080] In formula I-2, x Rs are the same or different and are independently C1-C8 alkyl, C4-C8 cycloalkyl, C6-C 15 Aryl or C7-C 15 of aralkyl.

[0081] The C1-C8 alkyl group includes a C1-C8 straight-chain alkyl group and a C3-C8 branched-chain alkyl group, and specific examples thereof may include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, 2-methylbutyl, 3-methylbutyl, 2,2-dimethylpropyl, n-hexyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 2,3-dimethylbutyl, 2,2-dimethylbutyl, 3,3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 2-methylhexyl, 3-methylhexyl, 4-methylhexyl, 5-methylhexyl, 2,2-dimethylpentyl, 2,3-dimethylpentyl, 2,4-dimethylbutyl, methylpentyl, 3,3-dimethylpentyl, 3,4-dimethylpentyl, 4,4-dimethylpentyl, 2-ethylpentyl, 3-ethylpentyl, n-octyl, 2-methylheptyl, 3-methylheptyl, 4-methylheptyl, 5-methylheptyl, 6-methylheptyl, 2,2-dimethylhexyl, 2,3-dimethylhexyl, 2,4-dimethylhexyl, 2,5-dimethylhexyl, 3,3-dimethylhexyl, 3,4-dimethylhexyl, 3,5-dimethylhexyl, 4,4-dimethylhexyl, 4,5-dimethylhexyl, 5,5-dimethylhexyl, 2-ethylhexyl, 3-ethylhexyl, 4-ethylhexyl, 2-n-propylpentyl and 2-isopropylpentyl.

[0082] Specific examples of the C4-C8 cycloalkyl group may include, but are not limited to, cyclobutyl, cyclopentyl, cyclohexyl, 4-methylcyclohexyl, 4-ethylcyclohexyl, 4-n-propylcyclohexyl and 4-n-butylcyclohexyl.

[0083] The C6-C 15Specific examples of the aryl group may include, but are not limited to, phenyl, naphthyl, 2-methylphenyl, 2-ethylphenyl, 4-methylphenyl, and 4-ethylphenyl.

[0084] In the present invention, the term "aralkyl" means that at least one hydrogen atom in an alkyl group is replaced by an aryl group, which can be represented by Ar d -N-, wherein d Ar are the same or different and are independently aryl, N is an alkyl group, and q is an integer from 1 to 3. 15 Specific examples of the aralkyl group may include, but are not limited to, phenylmethyl, phenylethyl, phenyl-n-propyl, phenyl-n-butyl, phenyl-t-butyl, phenyl-isopropyl, phenyl-n-pentyl, and phenyl-n-butyl.

[0085] Preferably, in formula I-2, x R are the same or different and are each independently C6-C 15 More preferably, in formula I-2, x R's are all phenyl.

[0086] In formula I-2, B is phosphorus, arsenic, sulfur or sulfoxide. Preferably, in formula I-2, B is phosphorus.

[0087] In formula I-2, y T are the same or different and are independently hydrogen or an anion. Preferably, in formula I-2, T is an anion. More preferably, in formula I-2, T is a halogen ion. Further preferably, in formula I-2, T is a chloride ion or a bromide ion. Particularly preferably, in formula I-2, T is a chloride ion.

[0088] In formula I-2, z is 2, 3 or 4. In formula I-2, x is 2 or 3. In formula I-2, y is 1, 2 or 3.

[0089] In a preferred embodiment, the compound represented by formula I-2 is (PPh3)3RhCl.

[0090] In step (3), the amount of hydrogenation catalyst can be selected according to the amount of acrylonitrile-butadiene rubber. Preferably, the mass of the hydrogenation catalyst is 0.01-5% of the mass of the acrylonitrile-butadiene rubber to improve the degree of hydrogenation of the hydrogenated product. More preferably, the mass of the hydrogenation catalyst is 0.05-1% of the mass of the acrylonitrile-butadiene rubber. Further preferably, the mass of the hydrogenation catalyst is 0.05-0.5% of the mass of the acrylonitrile-butadiene rubber. Still further preferably, the mass of the hydrogenation catalyst is 0.05-0.2% of the mass of the acrylonitrile-butadiene rubber.

[0091] According to the method of the present invention, in step (3), the auxiliary agent is one or more compounds selected from the group consisting of:

[0092] (A o M) p Y q(Formula II).

[0093] In formula II, o A's are the same or different and are independently C1-C8 alkyl, C4-C8 cycloalkyl, C6-C 15 Aryl or C7-C 15 of aralkyl.

[0094] Preferably, in Formula II, o A's are the same or different and are each independently C6-C 15 More preferably, in Formula II, o A's are all phenyl.

[0095] In formula II, M is selected from phosphorus or arsenic.

[0096] In formula II, q Y are the same or different and are each independently an anion. Preferably, in formula II, q Y are the same or different and are each independently a halogen ion. More preferably, in formula II, q Y are the same or different and are each independently a chloride ion or a bromide ion. More preferably, in formula II, Y is a chloride ion.

[0097] In formula II, o is 3, 4, 5 or 6; p is 1, 2 or 3; and q is 1, 2 or 3.

[0098] In step (3), from the perspective of further improving the hydrogenation reaction activity of the hydrogenation catalyst and further improving the hydrogenation degree of the hydrogenation product, the auxiliary agent is preferably (PPh4)Cl and / or (PPh4)Br.

[0099] According to the method of the present invention, the auxiliary agent in step (3) can be commercially available.

[0100] In step (3), the amount of the auxiliary agent can be selected according to the amount of the hydrogenation catalyst. Preferably, the mass of the auxiliary agent is 0.001-200% of the mass of the hydrogenation catalyst, so that the degree of hydrogenation of the hydrogenation product can be further improved. More preferably, the mass of the auxiliary agent is 0.002-160% of the mass of the hydrogenation catalyst. Further preferably, the mass of the auxiliary agent is 0.01-150% of the mass of the hydrogenation catalyst. Even further preferably, the mass of the auxiliary agent is 0.05-100% of the mass of the hydrogenation catalyst. Particularly preferably, the mass of the auxiliary agent is 0.1-80% of the mass of the hydrogenation catalyst, for example: 10-80%, or 10-20%.

[0101] According to the method of the present invention, in step (3), the ligand may be one or more of an organic phosphine, an organic cerium, a nitrogen-containing organic compound, a sulfur-containing organic compound and an oxygen-containing organic compound. The organic phosphine may be an organic monophosphine or an organic diphosphine. The ligand may be a ligand that reacts with L or R in the hydrogenation catalyst. xB is the same as L or R in the hydrogenation catalyst. x Preferably, the ligand is different from L or R in the hydrogenation catalyst. x B is the same. In a preferred embodiment, the ligand is an organic monophosphine and / or an organic diphosphine, and specific examples thereof may include but are not limited to one or more of triphenylphosphine, 1,3-bis(diphenylphosphino)propane and 1,4-bis(diphenylphosphino)butane. In a more preferred embodiment, the ligand is an organic monophosphine, which can further improve the degree of hydrogenation of the hydrogenated product. In a further preferred embodiment, the ligand is triphenylphosphine.

[0102] In step (3), the amount of the ligand can be selected according to the amount of the hydrogenation catalyst. Preferably, the mass of the ligand is 1-20 times the mass of the hydrogenation catalyst, which can further improve the degree of hydrogenation of the hydrogenated product. More preferably, the mass of the ligand is 4-15 times the mass of the hydrogenation catalyst. Further preferably, the mass of the ligand is 6-12 times the mass of the hydrogenation catalyst.

[0103] According to the method of the present invention, in step (3), the temperature of the hydrogenation reaction can be 50-180°C, preferably 60-150°C, more preferably 70-130°C, and more preferably 80-120°C. In step (3), the hydrogen pressure can be 0.1-15MPa, preferably 4-12MPa, more preferably 5-10MPa, and more preferably 6-8MPa, and the pressure is a gauge pressure. In step (3), the duration of contact between the metathesis reaction mixture and hydrogen can be 1-20 hours, preferably 3-16 hours, more preferably 4-12 hours, and more preferably 5-8 hours.

[0104] According to the method of the present invention, the organic solvent in the hydrogenation reaction mixture can be removed by conventional methods to obtain the hydrogenated nitrile rubber. For example, the organic solvent in the hydrogenation reaction mixture can be removed by one or more combinations of methods such as ethanol condensation and steam distillation to obtain a hydrogenated product, and then the solvent on the hydrogenated product is removed to obtain a hydrogenated nitrile rubber. There is no particular limitation on the method for removing the solvent on the hydrogenated product, and various methods commonly used by those skilled in the art can be used. In one embodiment, the method for removing the solvent on the hydrogenated product is vacuum drying, and the temperature of the vacuum drying can be 50-100°C, preferably 55-80°C, and more preferably 60-70°C. The duration of the vacuum drying can be selected according to the temperature of the vacuum drying. Generally, the duration of the vacuum drying can be 1-10 hours, preferably 5-8 hours.

[0105] According to a second aspect of the present invention, the present invention provides a hydrogenated nitrile rubber prepared by the method of the present invention.

[0106] The present invention is further described below with reference to the following examples, but the scope of the present invention is not limited thereby.

[0107] In the following examples and comparative examples, the degree of hydrogenation of hydrogenated nitrile rubber is determined by nuclear magnetic resonance spectroscopy, and the degree of hydrogenation is calculated by the method described in "Nuclear magnetic resonance analysis method for microstructure and hydrogenation degree calculation of hydrogenated nitrile rubber [J]. Petrochemical Industry, 2014, 43: 403-405".

[0108] In the following examples and comparative examples, the Mooney viscosity is tested according to the method specified in GB / T1232.1-2016 "Unvulcanized rubber - Determination by disc shear viscometer - Part 1: Determination of Mooney viscosity".

[0109] In the following examples and comparative examples, the method for determining the gel content is as follows: weigh w1 grams of dry gel, add chlorobenzene to prepare a 1 g / 100 mL solution, dissolve for 24 hours, pour the solution into a 360-mesh filter with a constant weight (w2 grams) and filter, then dry the 360-mesh filter containing insoluble matter to a constant weight, the weight is recorded as w3 grams, and the gel content is calculated using the following formula:

[0110] Gel content (ppm) = (w3-w2) / w1×10 6 .

[0111] In the following examples and comparative examples, (PPh3)3RhCl, (PPh4)Cl and (PPh4)Br were purchased from J&K Company.

[0112] In the following examples and comparative examples, butadiene-acrylonitrile rubber was purchased from Lanhua Company with a brand name of N21L, a cyanide content of 41% by mass, and a Mooney viscosity of 58.

[0113] In the following examples and comparative examples, unless otherwise specified, pressures are gauge pressures.

[0114] Preparation Example 1

[0115] This preparation example is used to illustrate the hydrogenation catalyst M 1 a M 2 b X m L n (P1) preparation method, wherein M 1 Rhodium, M 2 is ruthenium, X is chlorine, L is triphenylphosphine, a:b is 2:1, m is 4, and n is 9.

[0116] 4.5 g of PPh3 was dissolved in a hot ethanol solution at 70°C under argon protection, the dissolved solution was added to a reaction bottle and heated to reflux; 0.5 g of RhCl3·H2O and 0.23 g of RuCl3·H2O were weighed and dissolved in an ethanol solution under argon protection, and the ethanol solution of RhCl3·H2O and RuCl3·H2O was added dropwise to the reaction bottle, the reflux reaction was maintained for 2.5 hours, and then the temperature was lowered to 25°C, the reaction mixture was filtered, and the obtained solid phase material was washed with ether to obtain a powdered hydrogenation catalyst, in which Rh:Ru=2:1 (molar ratio).

[0118] Preparation Example 2

[0119] This preparation example is used to illustrate the hydrogenation catalyst M 1 a M 2 b X m L n (P2) preparation method, wherein M 1 Rhodium, M 2 is ruthenium, X is chlorine, L is triphenylphosphine, a:b is 3:1, m is 5, and n is 12.

[0120] 6 g of PPh3 was dissolved in a hot ethanol solution at 70°C under argon protection, the dissolved solution was added to a reaction bottle and heated to reflux; 0.75 g of RhCl3·H2O and 0.23 g of RuCl3·H2O were weighed and dissolved in an ethanol solution under argon protection, and the ethanol solution of RhCl3·H2O and RuCl3·H2O was added dropwise to the reaction bottle, the reflux reaction was maintained for 2.5 hours, and then the temperature was lowered to 25°C, the reaction mixture was filtered, and the obtained solid phase material was washed with ether to obtain a powdered hydrogenation catalyst, in which Rh:Ru=3:1 (molar ratio).

[0122] Preparation Example 3

[0123] This preparation example is used to illustrate the hydrogenation catalyst M 1 a M 2 b X m L n (P3) preparation method, wherein M 1 Rhodium, M 2 is ruthenium, X is chlorine, L is triphenylphosphine, a:b is 1:1, m is 3, and n is 6.

[0124] 3 grams of PPh3 were dissolved in a hot ethanol solution at 70°C under argon protection, the dissolved solution was added to a reaction bottle and heated to reflux; 0.25 grams of RhCl3·H2O and 0.23 grams of RuCl3·H2O were weighed and dissolved in an ethanol solution under argon protection, and the ethanol solution of RhCl3·H2O and RuCl3·H2O was added dropwise to the reaction bottle, and the reflux reaction was maintained for 2.5 hours, then the temperature was lowered to 25°C, the reaction mixture was filtered, and the obtained solid phase material was washed with ether to obtain a powdered hydrogenation catalyst, in which Rh:Ru=1:1 (molar ratio).

[0126] Preparation Example 4

[0127] This preparation example is used to illustrate the preparation method of the molecular weight regulating catalyst.

[0128] Under nitrogen protection, 760 mg of iodine, 848 mg of the compound represented by formula VI (purchased from J&K Technology Co., Ltd.) and 20 mL of dichloromethane were added to a 100 mL three-necked flask and stirred at room temperature (25°C) for 0.5 hours. The obtained mixture was separated by aluminum oxide column chromatography (developing solvent: dichloromethane), and the obtained eluent was concentrated and washed with cyclohexane to obtain 1.31 g of a yellow solid catalyst. The obtained catalyst was subjected to nuclear magnetic resonance hydrogen spectrum ( 1 H-NMR) and carbon nuclear magnetic resonance spectroscopy ( 13 C-NMR) analysis confirmed that the obtained catalyst had the structure shown in Formula VII.

[0129] 1 H-NMR (400MHz, DMSO) δ (ppm): 1.35-2.06 (m,33H), 1.81 (s,18H), 2.62 (m,4H), 6.11 (d,1H), 7.38-7.50 (m,5H), 7.59-7.67 (m,3H).

[0130] 13 C-NMR (100 MHz, DMSO) δ (ppm): 24.8, 25.5, 26.2, 26.3, 26.4, 26.6, 31.9, 32.1, 129.1, 129.2, 129.3, 129.5, 130.7, 134.2, 134.3, 193.0.

[0131]

[0132] In Formula VI and Formula VII, Cy is cyclohexyl.

[0134] Examples 1-17

[0135] Examples 1-17 are used to illustrate the preparation method of the hydrogenated nitrile rubber of the present invention, and the specific preparation method is as follows:

[0136] (1) dissolving the nitrile rubber in an organic solvent to obtain a nitrile rubber solution, and degassing the nitrile rubber solution;

[0137] (2) adding a molecular weight regulating catalyst to the nitrile rubber solution, and reacting under olefin metathesis reaction conditions to obtain a metathesis reaction mixture, wherein the contact conditions include: a reaction temperature of A° C. and a reaction time of B hours;

[0138] (3) adding a hydrogenation catalyst, a ligand and an auxiliary agent to the metathesis reaction mixture, then charging hydrogen, and reacting with stirring, wherein the reaction conditions include: a hydrogen pressure of CMPa, a reaction temperature of D°C, and a reaction time of E hours;

[0139] (4) The hydrogenation reaction mixture was condensed with ethanol to precipitate a hydrogenation product, and the hydrogenation product was vacuum dried at 60° C. for 8 hours to obtain a hydrogenated nitrile rubber.

[0140] The specific preparation conditions are listed in Table 1. The hydrogenation degree, Mooney viscosity and gel content of the obtained hydrogenated nitrile rubber were measured, and the results are listed in Table 1.

[0142] Comparative Examples 1-5

[0143] The hydrogenated nitrile rubber was prepared by the same method as in Example 1-17, except that the experimental conditions listed in Table 1 were used. The degree of hydrogenation, Mooney viscosity and gel content of the prepared hydrogenated nitrile rubber are listed in Table 1.

[0145] Comparing Examples 1, 2, 5 and 14 with Comparative Examples 1, 2, 3 and 5, it can be seen that according to the method of the present invention, the addition of the additive can obtain a higher degree of hydrogenation. Comparing Example 2 with Comparative Example 4, it can be seen that according to the method of the present invention, the olefin metathesis reaction is first carried out before the hydrogenation reaction, which can effectively reduce the Mooney viscosity of the product and also has a certain promoting effect on the improvement of the degree of hydrogenation of the product.

[0146] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

[0147]

[0148]

Claims

1. A method for preparing hydrogenated nitrile rubber, characterized in that: The method comprises the following steps: (1) dissolving the nitrile rubber in an organic solvent to obtain the nitrile rubber solution; (2) subjecting the nitrile rubber solution to a metathesis reaction under olefin metathesis reaction conditions to obtain a metathesis reaction mixture; (3) contacting the metathesis reaction mixture with hydrogen under hydrogenation reaction conditions in the presence of a hydrogenation catalyst system to obtain a hydrogenation reaction mixture, wherein the hydrogenation catalyst system comprises a hydrogenation catalyst, a ligand and an auxiliary agent; The hydrogenation catalyst is one or more selected from the compounds represented by formula I-1 and the compounds represented by formula I-2. M 1 a M 2 b X m L n (Formula I-1) In Formula I-1, M 1 Rhodium, M 2 For ruthenium, m X are the same or different and are each independently chlorine, bromine or hydrogen, n L's are the same or different, and are each independently an organic phosphine, an organic cerium, a nitrogen-containing organic compound, a sulfur-containing organic compound, or an oxygen-containing organic compound, 1≤a≤6, 1≤b≤3, 3≤m≤7, 6≤n≤21; (R x B) z R y (Formula I-2) In formula I-2, x R are the same or different and are independently selected from C1-C8 alkyl, C4-C8 cycloalkyl, C6-C 15 Aryl or C7-C 15 The aralkyl group, B is phosphorus, arsenic, sulfur or sulfoxide, y T are the same or different, and each independently represents hydrogen or an anion, z is 2, 3 or 4, x is 2 or 3, y is 1, 2 or 3; The auxiliary agent is one or more compounds selected from the group consisting of: (A o M) p Y q (Formula II) In formula II, o A's are the same or different and are independently C1-C8 alkyl, C4-C8 cycloalkyl, C6-C 15 Aryl or C7-C 15 The aralkyl group, M is phosphorus or arsenic, q Y are the same or different and are each independently an anion, o is 3, 4, 5 or 6, p is 1, 2 or 3, and q is 1, 2 or 3.

2. The method according to claim 1, wherein: In step (2), the metathesis reaction is carried out in the presence of a molecular weight regulating catalyst; Preferably, the molecular weight regulator is one or more selected from the compounds of formula III and the compounds of formula IV. In formula III and formula IV, G1 and G2 are each hydrogen, C2-C 20 Substituted or unsubstituted alkenyl, C2-C 20 Substituted or unsubstituted alkynyl, C1-C 20 Substituted or unsubstituted alkyl, C6-C 20 Substituted or unsubstituted aryl, C1-C 20 Carboxylate group, C1-C 20 Substituted or unsubstituted alkoxy, C2-C 20 Substituted or unsubstituted alkenyloxy, C2-C 20 Substituted or unsubstituted alkynyloxy, C6-C 20 Substituted or unsubstituted aryloxy, C1-C 20 Substituted or unsubstituted alkylthio, C1-C 20 substituted or unsubstituted alkylsulfonyl, or C1-C 20 a substituted or unsubstituted alkylsulfinyl group, E1, E2, E3 and E4 are each anionic ligands, F1, F2, F3 and F4 are each neutral ligands, In formula III, H is an anionic ligand, In formula III, c is an integer from 1 to 6; Preferably, in Formula III and Formula IV, G1 and G2 are each C6-C 20 A substituted or unsubstituted aryl group, more preferably a phenyl group; Preferably, in Formula III and Formula IV, E1, E2, E3 and E4 are each a halogen ion, more preferably a chloride ion; Preferably, in Formula III and Formula IV, F1, F2, F3 and F4 are each phosphine, amine, thioether, carbene, or substituted or unsubstituted imidazolidine, more preferably phosphine, carbene, or substituted or unsubstituted imidazolidine; Preferably, in formula III, H is a halogen ion, more preferably an iodide ion.

3. The method according to claim 2, wherein: In formula III and formula IV, G1 and G2 are each phenyl; In formula III, F1 is a phosphine, preferably a trialkylphosphine; In formula III, F2 is each substituted or unsubstituted imidazolidine; In formula IV, F4 and F3 are each a substituted or unsubstituted imidazolidine, or a phosphine, and the phosphine is preferably a trialkylphosphine; In formula III and formula IV, E1, E2, E3 and E4 are chloride ions; In formula III, H is an iodide ion.

4. The method according to claim 2 or 3, wherein: The imidazolidine is an imidazolidine represented by formula V, In Formula V, G3 and G4 are the same or different and are each independently C6-C 20 A substituted or unsubstituted aryl group; G3 and G4 are each independently preferably G5, G6, G7, G8 and G9 are each independently hydrogen or C1-C5 alkyl; G3 and G4 are more preferably 5. The method according to claim 1, wherein: In step (2), the amount of the molecular weight regulating catalyst is 0.002-5% by weight of the total amount of the nitrile rubber, preferably 0.005-1% by weight of the total amount of the nitrile rubber, and more preferably 0.006-0.5% by weight of the total amount of the nitrile rubber.

6. The method according to claim 1, wherein: In step (2), the contact between the molecular weight regulating catalyst and the nitrile rubber solution is carried out in the presence of at least one regulator, and the regulator is an olefin.

7. The method according to claim 6, wherein: The olefin is a monoolefin, preferably an α-olefin, and more preferably a C2-C 20 The alpha-olefin is preferably C2-C 10 α-olefins; Preferably, the mass of the regulator is 1-80% of the mass of the nitrile rubber, preferably 5-60%, more preferably 10-50%.

8. The method according to claim 1, wherein: In step (2), the contacting conditions include: a temperature of 30-150°C, preferably 40-120°C.

9. The method according to claim 1, wherein: In step (3), the amount of the ligand added is 1-20 times, preferably 4-15 times, the mass of the hydrogenation catalyst.

10. The method according to claim 1 or 9, wherein: In step (3), the amount of the additive added is 0.001-200% of the mass of the hydrogenation catalyst, preferably 0.002-160%, more preferably 0.01-150%.

11. The method according to any one of claims 1, 9 and 10, wherein: In formula I-1, X is chlorine, L is an organic monophosphine, and L is preferably triphenylphosphine; Preferably, in formula I-1, a:b is 1-3:1, preferably 2:1; Preferably, the compound represented by formula I-2 is (PPh3)3RhCl.

12. The method according to any one of claims 1 and 9-11, wherein: In step (3), the ligand is one or more of an organic phosphine, an organic cerium, a nitrogen-containing organic compound, a sulfur-containing organic compound, or an oxygen-containing organic compound; Preferably, the ligand is an organic monophosphine; More preferably, the ligand is triphenylphosphine.

13. The method according to any one of claims 1 and 9-12, wherein: In step (3), the auxiliary agent is (PPh4)Cl and / or (PPh4)Br.

14. The method according to any one of claims 1 and 9 to 13, wherein: In step (3), the hydrogenation reaction conditions include: temperature of 50-180° C., hydrogen pressure of 0.1-15 MPa, contact time of 1-20 hours, and the pressure is gauge pressure; Preferably, in step (3), the hydrogenation reaction conditions include: temperature of 60-150° C., hydrogen pressure of 4-12 MPa, contact time of 3-16 hours, and the pressure is gauge pressure.

15. The method according to any one of claims 1 and 9 to 14, wherein: In step (3), the amount of the hydrogenation catalyst added is 0.01-5% of the mass of the nitrile rubber, preferably 0.05-1%, and more preferably 0.05-0.5%.

16. The method according to claim 1, wherein: In step (1), the mass percentage concentration of nitrile rubber in the nitrile rubber solution is 2-15%, preferably 4-12%.

17. The method according to claim 1 or 16, wherein: In step (1), the organic solvent is one or more of aromatic hydrocarbons, halogen-substituted aromatic hydrocarbons, halogenated alkanes, ketones, oxacycloalkanes and amides; Preferably, in step (1), the organic solvent is one or more of benzene, toluene, xylene, chlorobenzene, dichlorobenzene, trichlorobenzene, acetone, butanone, tetrahydrofuran, dioxane and N,N-dimethylformamide.

18. The method according to any one of claims 1, 16 and 17, wherein: Step (1) also includes degassing the nitrile rubber solution.

19. The preparation method according to any one of claims 1 to 18, wherein: The nitrile rubber is a binary nitrile rubber and / or a ternary nitrile rubber; Preferably, the nitrile rubber is butadiene-acrylonitrile rubber, butadiene-(meth)acrylonitrile rubber, 2-methyl-1,3-butadiene-acrylonitrile rubber, 2-methyl-1,3-butadiene-(meth)acrylonitrile rubber, butadiene-acrylonitrile-acrylic rubber, butadiene-acrylonitrile-methyl acrylate rubber, butadiene-acrylonitrile-ethyl acrylate rubber, butadiene-acrylonitrile-tert-butyl acrylate rubber, butadiene-acrylonitrile-butyl acrylate rubber, butadiene-acrylonitrile-(meth)acrylic rubber, butadiene-acrylonitrile-methyl (meth)acrylate rubber, butadiene-acrylonitrile-ethyl (meth)acrylate rubber, butadiene-acrylonitrile-tert-butyl (meth)acrylate rubber, butadiene-acrylonitrile One or more of nitrile-(meth)acrylate butyl rubber, butadiene-(meth)acrylonitrile-acrylic rubber, butadiene-(meth)acrylonitrile-methyl acrylate rubber, butadiene-(meth)acrylonitrile-ethyl acrylate rubber, butadiene-(meth)acrylonitrile-tert-butyl acrylate rubber, butadiene-(meth)acrylonitrile-butyl acrylate rubber, butadiene-(meth)acrylonitrile-(meth)acrylic rubber, butadiene-(meth)acrylonitrile-methyl (meth)acrylate rubber, butadiene-(meth)acrylonitrile-ethyl (meth)acrylate rubber, butadiene-(meth)acrylonitrile-tert-butyl (meth)acrylate rubber and butadiene-(meth)acrylonitrile-butyl (meth)acrylate rubber; More preferably, the nitrile rubber is butadiene-acrylonitrile rubber and / or butadiene-(meth)acrylonitrile rubber.

20. A hydrogenated nitrile rubber prepared by the method described in any one of claims 1 to 19.

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